Other Physics Answers

If a 5-kg object experiences a 10-N force for a duration of 0.10-second, then what is the momentum change of the object?

6.5 kg chunk of ice at -12⁰C is placed in a 0.22 kg of water at 22⁰C. Ignore any heat flow with the surroundings, including the container, assume the final mixture is ice. Determine the following; 

heat lost or gained by water    

Why do helicopters always have a set of two blades?

In tearing a plastic bag from a roll, it is easier to do by a quick jerk. Why?

When two cars collide, the forces they received are equal but opposite. What about their acceleration?

If you hit somebody from behind, his head seems to snap backward. Why?

A wire made of copper is found to have a change in resistance of 17% after its temperature change. If the resistance of this wire was 8.66 Ω at 20 ⁰C, and the resistivity after the change in temperature is found to have decreased, determine the following: 

the final temperature of the wire after the change in temperature.                                                 

Select one:

 -22.5 ⁰C

 22.5 ⁰C 

 45 ⁰C

 -5 ⁰C

The velocity along a stream line passing through the origin is given by v=2V=2√x^2+y^2 what is the velocity and acceleration at (4;3)

Determine the velocities of two masses after collision of a 6 – kg mass moving with a velocity of 6 m/s and a 4 – kg mass that is moving with a velocity of 3 m/s if there are no external forces acting on them.

A. e=Vs/Va

B. What are the given data?

C-1. Calculate using the law on conservation of momentum: (equation 1)

mAuA+mBuB=mAVA+mBVB

C-2. and the coefficient of restitution: (equation 2)

e=VB-VA/uB-uA

D. Substitute in equation 1:

E. Substitute in equation 2:

F. Conclusion:

A 3.56 kg block resting on a smooth horizontal surface is attached to a string that passes over a frictionless pulley as shown in the figure. The pulley has a radius of 0.28 m. A force of 7.5 N pulls the other end of the string. As a result, the block moves a distance of 0.2 m starting from rest. Find the (a) acceleration of the block, (b) angular acceleration of the pulley, and (c) moment of inertia of the pulley.