Physics Answers

A football was kicked at an angle of 450 with an initial velocity of 25.7m/s.

a. What was the horizontal displacement of the ball?

A fire cracker was launched in the air at an angle of 750 with an initial velocity around 18.5m/s.

a. How high can the fire cracker reach?

A 100W,250V lamp is connected in series with a 100W,200V lamp across a 250V supply mains. Calculate the current drawn from the supply mains and voltage across each lamp. Assume lamp resistance.

Assume that v=k f l m where k is the constant of proportionality and ABC are number we intend to find by dimension. Prove dimensionally that v=k√fl/m

If you pass a comb through your hair and it acquires a charge of -0.1 µC, how many excess electrons does
it carry? What conclusions can you reach by applying the law of conservation of charge to this situation?

prove that the distance between two points is invariert under gyalilean transformation

Two charged particles are enclosed in an infinite cylindrical container. The
charge of the first particle is +20 nC and it is located 35 cm away from the other
charged particle. Calculate the charge of the second particle if the net electric
force of the system is equal to 2.83x10-5 N and is attractive.

What is the spring constant k if a spring stretches .5m when a 10 kg mass is suspended from it?
F = k x

A 2-kg mass hangs at the end of a spring whose constant is k = 400 N/m. The mass is displaced (-) a
distance of 12cm and released. What is the acceleration at the instant the displacement is x = +7 cm?
a = (k / m) A or a = k x / m