# Samantha

### Physics - How do I solve this vector?

For the following three vectors, what is ?

Upper A Overscript right-arrow EndScripts equals 3.00 i Overscript ̂ EndScripts plus 4.00 j Overscript ̂ EndScripts minus 3.00 k Overscript ̂ EndScripts

Upper B Overscript right-arrow EndScripts equals negative 2.00 i Overscript ̂ EndScripts plus 4.00 j Overscript ̂ EndScripts plus 3.00 k Overscript ̂ EndScripts

Upper C Overscript right-arrow EndScripts equals 7.00 i Overscript ̂ EndScripts minus 8.00 j Overscript ̂ EndScripts

1 AnswerPhysics3 months ago### A proton moves through a uniform magnetic field.?

A proton moves through a uniform magnetic field given by ModifyingAbove Upper B With right-arrow equals left-parenthesis 8.97ModifyingAbove i With caret minus 20.7ModifyingAbove j With caret plus 20.8ModifyingAbove k With caret right-parenthesis mT. At time t1, the proton has a velocity given by v Overscript right-arrow EndScripts equals v Subscript x Baseline i Overscript caret EndScripts plus v Subscript y Baseline j Overscript caret EndScripts plus left-parenthesis 1.70 km/s right-parenthesis k Overscript caret EndScripts and the magnetic force on the proton is Upper F Overscript right-arrow EndScripts Subscript Upper B Baseline equals left-parenthesis 3.64times 10 Superscript negative 17 Baseline Upper Nright-parenthesis i Overscript caret EndScripts plus left-parenthesis 1.58times 10 Superscript negative 17 Baseline Upper Nright-parenthesis j Overscript caret EndScripts . (a) At that instant, what is vx? (b) At that instant, what is vy?

2 AnswersPhysics2 years ago### An air bubble of 20 cm3 volume is at the bottom of a lake 35 m deep where the temperature is 4.0°C.?

An air bubble of 20 cm3 volume is at the bottom of a lake 35 m deep where the temperature is 4.0°C. The bubble rises to the surface, which is at a temperature of 29°C. Take the temperature of the bubble's air to be the same as that of the surrounding water. Just as the bubble reaches the surface, what is its volume?

1 AnswerPhysics3 years ago### An insulated Thermos contains 160 cm3 of hot coffee at 92.0°C. You put in a 19.0 g ice cube at its melting point to cool the coffee.?

An insulated Thermos contains 160 cm3 of hot coffee at 92.0°C. You put in a 19.0 g ice cube at its melting point to cool the coffee. By how many degrees has your coffee cooled once the ice has melted and equilibrium is reached? Treat the coffee as though it were pure water and neglect energy exchanges with the environment. The specific heat of water is 4186 J/kg·K. The latent heat of fusion is 333 kJ/kg. The density of water is 1.00 g/cm3.

1 AnswerPhysics3 years ago### Find the volume V of the solid obtained by rotating the region bounded by the given curves about the specified line.?

y = 3 squareroot 25 − x2, y = 0, x = 3, x = 4; about the x-axis.

*Photo includes question and graphs

3 AnswersMathematics3 years ago### A diver of weight 500 N stands at the end of a diving board of length L = 4.1 m and negligible mass (the figure).?

A diver of weight 500 N stands at the end of a diving board of length L = 4.1 m and negligible mass (the figure). The board is fixed to two pedestals separated by distance d = 0.75 m. Take the upward direction to be positive. Of the forces acting on the board, what are (a) the force from the left pedestal and (b) the force from the right pedestal?

1 AnswerPhysics3 years ago### Two uniform solid cylinders, each rotating about its central (longitudinal) axis, have the same mass of 2.44 kg.?

Two uniform solid cylinders, each rotating about its central (longitudinal) axis, have the same mass of 2.44 kg and rotate with the same angular speed of 188 rad/s, but they differ in radius. What is the rotational kinetic energy of (a) the smaller cylinder, of radius 0.287 m, and (b) the larger cylinder, of radius 0.634 m?

1 AnswerPhysics3 years ago### A car starts from rest and moves around a circular track of radius 22.0 m. Its speed increases at the constant rate of 0.480 m/s2.?

A car starts from rest and moves around a circular track of radius 22.0 m. Its speed increases at the constant rate of 0.480 m/s2. (a) What is the magnitude of its net linear acceleration 16.0 s later? (b) What angle does this net acceleration vector make with the car's velocity at this time?

1 AnswerPhysics3 years ago### A flywheel turns through 36 rev as it slows from an angular speed of 9.8 rad/s to a stop.?

A flywheel turns through 36 rev as it slows from an angular speed of 9.8 rad/s to a stop. (a) Assuming a constant angular acceleration, find the time for it to come to rest. (b) What is its angular acceleration? (c) How much time is required for it to complete the first 18 of the 36 revolutions?

1 AnswerPhysics3 years ago### A block with mass m = 3.92 kg is placed against a spring on a frictionless incline with angle θ = 36.1° (see the figure).?

A block with mass m = 3.92 kg is placed against a spring on a frictionless incline with angle θ = 36.1° (see the figure). (The block is not attached to the spring.) The spring, with spring constant k = 18 N/cm, is compressed 11.5 cm and then released. (a) What is the elastic potential energy of the compressed spring? (b) What is the change in the gravitational potential energy of the block-Earth system as the block moves from the release point to its highest point on the incline? (c) How far along the incline is the highest point from the release point?

1 AnswerPhysics3 years ago### In the figure, a block of mass m = 17 kg is released from rest on a frictionless incline of angle θ = 35°.?

In the figure, a block of mass m = 17 kg is released from rest on a frictionless incline of angle θ = 35°. Below the block is a spring that can be compressed 2.0 cm by a force of 300 N. The block momentarily stops when it compresses the spring by 4.0 cm. (a) How far does the block move down the incline from its rest position to this stopping point? (b) What is the speed of the block just as it touches the spring?

Physics3 years ago### Figure (a) applies to the spring in a cork gun (Figure (b); it shows the spring force as a function of the stretch or compression of spring.?

Figure (a) applies to the spring in a cork gun (Figure (b)); it shows the spring force as a function of the stretch or compression of the spring. The spring is compressed by 3.00 cm and used to propel a 3.40 g cork from the gun. (a) What is the speed of the cork if it is released as the spring passes through its relaxed position? (b) Suppose, instead, that the cork sticks to the spring and stretches it 1.60 cm before separation occurs. What now is the speed of the cork at the time of release?

1 AnswerPhysics3 years ago### The figure shows a thin rod, of length L = 1.70 m and negligible mass, that can pivot about one end to rotate in a vertical circle.?

The figure shows a thin rod, of length L = 1.70 m and negligible mass, that can pivot about one end to rotate in a vertical circle. A heavy ball of mass m = 11.0 kg is attached to the other end. The rod is pulled aside to angle θ0 = 11.0° and released with initial velocity v Overscript right-arrow EndScripts Subscript 0 = 0. As the ball descends to its lowest point, (a) how much work does the gravitational force do on it and (b) what is the change in the gravitational potential energy of the ball-Earth system? (c) If the gravitational potential energy is taken to be zero at the lowest point, what is its value just as the ball is released?

1 AnswerPhysics3 years ago### The figure gives the acceleration of a 2.0 kg particle as an applied force moves it from rest along an x axis from x = 0 to x = 9.0 m.?

The figure gives the acceleration of a 2.0 kg particle as an applied force moves it from rest along an x axis from x = 0 to x = 9.0 m. The scale of the figure's vertical axis is set by as = 8.0 m/s2. How much work has the force done on the particle when the particle reaches (a) x = 4.0 m, (b) x = 7.0 m, and (c) x = 9.0 m? What is the particle's speed and direction (give positive answer if the particle moves along x axis in positive direction and negative otherwise) of travel when it reaches (d) x = 4.0 m, (e) x = 7.0 m, and (f) x = 9.0 m?

1 AnswerPhysics3 years ago### A 12 kg body is moving through space in the positive direction of an x axis with a speed of 210 m/s.?

A 12 kg body is moving through space in the positive direction of an x axis with a speed of 210 m/s when, due to an internal explosion, it breaks into three parts. One part, with a mass of 4.3 kg, moves away from the point of explosion with a speed of 160 m/s in the positive y direction. A second part, with a mass of 3.5 kg, moves in the negative x direction with a speed of 480 m/s. What are the (a) x-component and (b) y-component of the velocity of the third part? (c) How much energy is released in the explosion? Ignore effects due to the gravitational force.

1 AnswerPhysics3 years ago### A soccer player kicks a soccer ball of mass 0.45 kg that is initially at rest.?

A soccer player kicks a soccer ball of mass 0.45 kg that is initially at rest. The player's foot is in contact with the ball for 1.50 × 10-3 s, and the force of the kick is given by F(t) = [(7.61 × 105)t - (5.07 × 108)t2] N for 0 less-than-or-equal-to t less-than-or-equal-to 1.50 times 10 Superscript negative 3 Baseline s, where t is in seconds. Find the magnitudes of the following: (a) the impulse on the ball due to the kick, (b) the average force on the ball from the player's foot during the period of contact, (c) the maximum force on the ball from the player's foot during the period of contact, and (d) the ball's speed immediately after it loses contact with the player's foot.

1 AnswerPhysics3 years ago### A pendulum consists of a 3.3 kg stone swinging on a 4.3 m string of negligible mass.?

A pendulum consists of a 3.3 kg stone swinging on a 4.3 m string of negligible mass. The stone has a speed of 8.2 m/s when it passes its lowest point. (a) What is the speed when the string is at 58 ˚ to the vertical? (b) What is the greatest angle with the vertical that the string will reach during the stone's motion? (c) If the potential energy of the pendulum-Earth system is taken to be zero at the stone's lowest point, what is the total mechanical energy of the system?

1 AnswerPhysics3 years ago### A 884 g block is released from rest at height h0 above a vertical spring with spring constant k = 570 N/m and negligible mass.?

A 884 g block is released from rest at height h0 above a vertical spring with spring constant k = 570 N/m and negligible mass. The block sticks to the spring and momentarily stops after compressing the spring 14.0 cm. How much work is done (a) by the block on the spring and (b) by the spring on the block? (c) What is the value of h0? (d) If the block were released from height 6h0 above the spring, what would be the maximum compression of the spring?

1 AnswerPhysics3 years ago### A 2.10 kg snowball is fired from a cliff 12.2 m high with an initial velocity of 15.4 m/s, directed 45.0° above the horizontal.?

A 2.10 kg snowball is fired from a cliff 12.2 m high with an initial velocity of 15.4 m/s, directed 45.0° above the horizontal. (a) Using energy techniques, find the speed of the snowball as it reaches the ground below the cliff. What is that speed (b) if the launch angle is changed to 45.0° below the horizontal and (c) if the mass is changed to 5.10 kg?

2 AnswersPhysics3 years ago### You drop a 2.90 kg book to a friend who stands on the ground at distance D = 12.0 m below.?

You drop a 2.90 kg book to a friend who stands on the ground at distance D = 12.0 m below. If your friend's outstretched hands are at distance d = 1.30 m above the ground (see the figure), (a) how much work Wg does the gravitational force do on the book as it drops to her hands? (b) What is the change ΔU in the gravitational potential energy of the book-Earth system during the drop? If the gravitational potential energy U of that system is taken to be zero at ground level, what is U (c) when the book is released and (d) when it reaches her hands? Now take U to be 100 J at ground level and again find (e) Wg, (f ) ΔU, (g) U at the release point, and (h) U at her hands.

1 AnswerPhysics3 years ago