Physics Answers

If the reflective Index of a medium is 1.5cm and the angle of Incidence=60 calculate the angle of refraction

A current of 50.0A

50.0A flows through a cross-section of a wire. After six hours, what is the total mass of all of the electrons which have passed through the cross-section? Give your answer in milligrams (mg) and to three significant figures.

A ball is thrown vertically upwards with an initial velocity of 30 m/s.

Using a time step of 0.02 s up to 6.20 s, plot the graph of the vertical distance versus time for this ball.

Hint ; Motion under gravity is described by the equation : 𝑣𝑦 = 𝑣𝑜𝑦𝑡 +1/2𝑔𝑡^2

and gravitational acceleration 𝑔 is here taken as negative.

(i) To what maximum height does the ball rise?

(ii) What is the index of time at maximum height?

(iii) How long does it take the ball to ascend to maximum height?

(iv) How long does it take the ball to hit the ground?

(v) What happens to the ball if the sign for gravitational acceleration is taken as positive?

A hundred 1.0 ohm resistors are to be connected in a circuit. All resistors must be connected in the circuit such that current flows through them. What is the least equivalent resistance you could get in such a circuit? Give your answer in ohms to two significant figures

A typical incandescent bulb has an efficiency of about 10%. What current is needed for a bulb with a resistance of 1.5×102Ω to output power of 6.0 W?

A typical incandescent bulb has an efficiency of about 10%. What current is needed for a bulb with a resistance of (1.5×10^2) Ω  to output power of 6.0 W?

Before hanging new William Morris wallpaper in her bedroom, Brenda sanded the walls lightly to smooth out some

irregularities on the surface. The sanding block weighs 1.90 N and Brenda pushes on it with a force of 3.00 N at an angle

of 30.0° with respect to the vertical, and angled toward the wall.What is the coefficient of kinetic friction between the wall and the block?

Two charges, Q and -Q, are held stationary at a distance of 4 m. Q= 5x10^-6 is given. a) What is the potential difference VB-VA? b) A point charge of mass 0.3 g and charge 2x10^-6 C, initially at rest, leaves point A. What is the velocity at B?

(The distance between Q and point A is 2 m. The distance between A and B are 1 m. The distance between B and -Q is 1 m.)

So how would you calculate the force of F needed to keep the engine stationary by first resolving the forces into their horizontal and vertical components.

Two cats A and B, jump from the top of a vertical cliff. Cat A just drops and reaches the ground in 3.50secs, while cat B jumps horizontally with an initial speed of 95cm/secs. How far from the base of the cliff will cat B hit the ground?