Physics Answers

A curve in a road has a radius of 240 m. If the road surface is level and on a  

               rainy day the coefficient of static friction is 0.48, what is the maximum speed 

               at which the car can negotiate this curve? 

Consider cobalt-60 (⁶⁰CO) with a half-line of 5.25 years. How many years will it take for its activity to decrease to one-fourth of its original amount?

Suppose a space probe moves away from the Earth at a speed 0.350c. It sends a radio wave message back to the Earth at a frequency of 1.50 GHz. At what frequency is the message received on the Earth?

Calculate the rest energy of a single proton. Use the equation E=mc² to solve the problem.

Suppose a spaceship is approaching the Earth at half the speed of light and shoots a canister at a speed of 0.750c.

a). At what velocity will an Earth-bound observer see the canister if it is shot directly towards the Earth?

b). If it shot directly away from earth?

A 1.0 kg object is brought to planet Mercury where the acceleration due to gravity is 0.38 times its value on Earth. (a) What is the weight of the object on Earth? (b) What is the mass of the object on Mercury? What is its weight on Mercury?

Find the approximate angle between vectors: 𝐒 = (2, 3, 5) and 𝐓⃗ = (1, 6, -4).

A box moves 10 m horizontally when force F=20 N is applied at an angle θ=120°. What is

the work done on the box by the force during the displacement?

Meldrick is playing foot jump. The ball in his foot jump is in uniform

circular motion and makes 10 revolutions in 4.0 seconds.

a) What is its period?

b) If the length of the plastic cord that holds the ball is 0.8 meter, what is its tangential velocity?

c) If the ball has a mass of 3 grams, how much force is acting the ball to keep it in uniform circular motion?

d) What is the centripetal acceleration of the ball?

If the ball has a mass of 3 grams, how much force is acting the ball to keep it uninform circular motion