Other Physics Answers

A 50 N block is placed on a smooth inclined plane which is 5 meters long and 3 meters high. (a) What force parallel to the plane and applied to the block will keep the block in equilibrium? (b) What force is applied by the plane to the block? 

What constant force is needed in order to increase the speed of a car from 30 km/h to 

60 km/h in a time of 6s if the mass of the car is 2400 kg?

4. The average intensity of sunlight,𝑆̅ at the upper atmosphere is approximately1400𝑊𝑚−2. The average distance between Earth and the Sun is1.50 × 1011 𝑘𝑚, and the mean radius of Earth is 6370 𝑘𝑚.

a) Calculate the amplitudes of the electric and magnetic fields in the sunlight

b) Calculate the average power generated by the Sun

c) Calculate the total power intercepted by Earth

The spring under the action of a force of 4 N lengthened by 5 mm. Determine the weight of the weight that will extend this spring by 16 mm.

4. Nitrogen with a pressure of 1.0×105Pa and a volume of 0.0082m3 from the initial temperature of 300K. This gas is heated to 400K according to the following two processes. How much heat does it need to absorb? Which process requires more heat? why?

 (1) The volume does not change, (2) The pressure does not change

By applying the point for of OHM’s Law to a cylindrical conductor derive the expression V=IR . Assume that J and E are uniform. 

1. What is the coefficient of performance of an ideal heat pump that has heat transfer from a cold temperature of −25.0ºC to a hot temperature of 40.0ºC?
2. Suppose you have an ideal refrigerator that cools an environment at−20.0ºC and has heat transfer to another environment at 50.0ºC. What is its coefficient of performance?

The young modulus of elasticity is defined as E=F/A/e/a

Obtain the dimension of E where f= force A= area and l are lengths

The constant of a spring is 480 N/m.

How much elastic potential energy is stored in the spring if the spring is compressed a distance of 6.4 cm?

What is the force being used to compress the spring?

Use a graph to find the resistance ܴ଴ at 0 °C and the temperature coefficient ߙ ,where the resistance ܴ ൌ ܴ଴ሺͳ ൅ ߙܶሻ for a sample of wire giving the following data: ܴሺȳሻ 2.0700 2.1465 2.2225 2.2990 2.3740 2.4515 T (°C) 10 20 30 40 50 60