Physics Answers

An aluminum wire with a diameter of 1.02 mm and volume of 1.57x10-5 m3, has a battery attached to it with an emf of 30 volts. Find (a) the resistance of the wire and (b) the corresponding current.

A tesla car needs to charge its 350-volt model and must send about 715 amps through its cabling to the battery. What is the rate of electron flow through the cable for the current involved?

A height of 0.81m of a column of liquid (x) exerts the same pressure as a heavy box of weight 68,040N the base area of the box is 10m^2 what is the density of liquid (x)

A copper cylinder has a radius of 2.5 cm and a length of 5.6 cm at 20 degree Celsius. The rod is heated until its temperature is 85 degree Celsius. Find the density of the copper at 85 degree Celsius. If the density of the copper at 20 degree Celsius is 8,960 kg/m^3

The near point of a patient's eye is 50.0cm. What focal length must a corrective lens have to enable the eye to see clearly an object 25cm away? Neglect the eye-lens distance

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 versustime 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.

NB:Show calculations for the answer.

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

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

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

(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

film of refractive index 1.50 and

thickness 0.25 mm is introduced in the

path of one of the interfering beams of a

Michelson's interferometer. It causes

600 dark fringes to sweep across the

field of view. Calculate the wavelength

of light used.

Using Maxwell's equations for free space, show 

that light is an electromagnetic wave.

A box of mass 500kg is druged along a level ground at a speed of 12metres per second.if the force of friction between the box and the floor is 1200newtons .calculate the power developed?

A man in a sled, with a total mass of 125 kg, slides down a grassy hill and reaches a speed of 8 m/s at the bottom. If a pile of grass can exert a constant force of 250 N, how fast will the sled stop?