Other Physics Answers

Someday a person will walk on Mars, which is 5.6 x 10¹⁰ m from the earth at the closest approach. Determine the minimum time that will be required for a message from Mars to reach the earth via radio waves.

Question 1 options:

A) 

290 s

B) 

No option is correct

C) 

190 s

D) 

490 s

E) 

390 s

A volleyball is served overhead at an angle of 45 degrees above the horizontal at a speed of 9.8m/s. Show that the ball will just barely make it over the net and just about 2 meters on the other side of the net. Use projectile motion and free fall to calculate

a. The initial horizontal and vertical velocity 

b. The time it takes the ball to horizontally reach the net

1. A 550 g mass is tied to a string and made to move in a vertical circle of radius 55 cm at a constant speed. The tension in the string ranges from 2.0 N to 12.7 N. 

a. At what point is the tension a maximum? When is it a minimum?

b. Determine the speed of the mass.

1. A 200 g ball moves in a vertical circle on the end of a 50 cm long string, with no additional input of energy. If its speed at the bottom is 10 m s-1, calculate:

a. The velocity at the top of the circle

b. The tension at the top of the circle

A rollercoaster is designed with a 10 m tall vertical circular loop. Calculate the minimum speed necessary to get around the loop without falling down.

Garen observed his athletic friends, Aya and Marisa, run. The two girls ran in a 1.5-km straight dirt road. Marisa was a given a ten-second head-start. When Aya ran, she caught up with Marisa, who ran at 3.75 m/s. Both of them finished the 1000 m run, with Aya measured to finish the track at 375 seconds.

How fast was Aya?

How far did Marisa run after ten seconds?

Find the time Aya caught up alongside Marisa.

Find the distance where both runners met.

How long did Marisa run before she could finish the sprint?

Jayce threw his softball high in the air as Yukari looked down from her two-storey home to see how high he threw it. Jayce threw his ball high enough to reach the floor of the second storey. If Jayce threw the ball at an initial velocity of 30 m/s, and an initial height of 1.22 m, with one storey equivalent to at least 3.05 meters.

How fast is the ball after 0.2 seconds?

With the initial values, how high will the ball fly after 3 seconds?

if i double the distance between two objects,what happens to their gravitional force

• A 18Ω resistor and a 30Ω resistor are first connected in parallel and then in series with a voltage source of 12V. Find the effective resistance and current in each of the connections of the circuit.

• A 10Ω resistor is connected in parallel to 32Ω resistor and a voltage source of 24V. Find the effective resistance and total current provided in the circuit. Determine the current in each of the resistors.

• A 150Ω resistor is connected in series to a1kΩ resistor and to a battery of 127V. Find the effective resistance and current in the circuit.