Physics Test 97

Which of the following is a CORRECT statement ?

A projectile travels at θ below horizontal 1 sec after projection as shown. What is the value of θ ?

An electron in a research apparatus follows a circular path. On the electron's first circuit of the apparatus, its speed is v₀ and the radius of its circular path is R. Each time it makes one circuit, it passes a short region where it receives a "kick" and gains an additional speed of v₀/100. The electron follows a circular path such that the magnitude of its acceleration is always the same. What is the radius of the circular path after the electron has received 10 kicks ?

A square of mass m is made of thin wire with sides of length a. Calculate the rotational inertia about the z-axis.

If we want that a simple pendulum oscillates with same time period in summer as it did in winter, what changes to the simple pendulum should we do during summer ?

An igloo, a hemispherical enclosure built of ice (k = 1.67 J/m-s°C), has an inner radius of 2.50 m. The thickness of the ice is 0.5 m. At what rate must thermal energy be generated to maintain the air inside the igloo at 5°C when the outside temperature is –40°C ? Ignore all thermal energy losses through the ground or by air currents.

Assume temperature of 27°C, p = 10⁵ Pa, n = 1 moles, diameter of air molecules as 10^–10m, which of the following is correct?

A car is moving towards a stationary observer at a speed of 108 km/hr. The speed of sound is 330 m/s. If the observer hears the frequency of horn as 550 Hz, what frequency will he hear after the car has passed ?

Two blocks of same mass but different density ρ₁ & ρ₂ are floating in water. Block–2 has higher fraction of its volume submerged in water. If buoyant force on them are B₁ & B₂ :-

A plastic ball is rising in water with terminal speed v. If we use a different plastic whose density is double that of the original ball but still less than density of water, keeping the radius same, the terminal speed would be :-