Other Physics Answers

A He-Ne laser having an emergent beam diameter of 1 cm is flashed on to the moon surface. If the distance between the earth and moon is 3,84,403 km, what would be the diameter of the laser beam spot on the moon?

What average net force is required to bring a 1500kg car to rest from a speed of 100km/h within a distance of 55m?

Travelling in a mountainous area, a bus of mass 3 tons reaches the edge of a steep valley. There is a 1 km vertical drop to reach the valley below, but 20 km of road to get there. What gravitational potential energy? Will the bus lose in making its descent to the valley bottom?

A block of bricks is raised vertically to a bricklayer at the top of a wall using a pulley system. If the block of bricks has a mass of 24 kg, what is its weight? It is raised 3.0 m. Calculate its increase in gravitational potential energy when it reaches the top of the wall.

Water in an enclosed tank is subjected to a gauge pressure of 2x10^4 Pa, applied by a compressed air introduced into the top of the tank. There is a small hole (diameter = 4 cm) in the side of the tank 5 m below the level of the water. Calculate the discharge rate.

Kim and mike are on opposing dodgeball teams. Kim grabs a ball of mass 0.400 kg and throws it with a speed of 1.2m/s at the same time that Kim is throwing her ball mike had a slightly lighter under inflated ball with mass 0.35kg and throws it at Kim with a speed of 1.8m/s, his ball travels at an angle of 75 degrees to kim. As a result of the collision kim’s ball is deflected at an angle of 30 degrees from its original path with a speed of 1.6m/s. Determine the speed and angle of mike’s ball do not assume the collision is elastic.

A mass of 55 g hangs from a vertical spring how can you find the spring constant, is the answer a) 319n/m, b) 9.3n/m c) -0.00094 n/m d)320n/m

8.

 The charged capacitor in question 7. is then isolated from the battery and a dielectric sheet 

inserted to completely fill the space between the plates. The potential difference between the 

plates drops to 1000 V. Find the dielectric constant of the sheet.

A boy weighing 445 N swings on a 2-m long swing. If his horizontal speed at the lowest point is 3 m/s, what total force must the ropes holding the swing be able to withstand?

Calculate the specific heat of a substance if 420 calories is needed to raise the temperature of

this 75 grams substance from 15 ᵒC to 50 ᵒC.