Answer:
option ( a ) is correct .
Explanation:
Escape velocity on the earth = √ ( 2 GM / R )
where G is universal gravitational constant , M is mass of the earth and R is radius .
V₀ = √ ( 2 GM / R )
escape velocity on the planet where mass is equal is earth's mass and radius is 4 times that of the earth
Radius of the planet = 4 R
escape velocity of planet = √ ( 2 GM / 4R )
= .5 x √ ( 2 GM / R )
= .5 V₀
option ( a ) is correct .
The river that flows through Rome is the Tiber.
Answer:
-24.28571 rad/s²
29.57239 revolutions
3.91176 seconds
52.026478 m
Explanation:
= Tangential acceleration = -6.8 m/s²
r = Radius of wheel = 0.28
= Initial angular velocity = 95 rad/s
= Angle of rotation
= Final angular velocity
t = Time taken
Angular acceleration is given by

The angular acceleration is -24.28571 rad/s²

The number of revolutions is 29.57239

The time it takes for the car to stop is 3.91176 seconds
Linear distance

The distance the car travels is 52.026478 m
Answer:
A new substance was formed
Explanation:
According to this question, a shiny and flexible metal called Magnesium (Mg) is burnt in air to produce a white powder that has no shiny or flexible properties, however, has more weight than the magnesium metal itself.
This is possible because a CHEMICAL CHANGE has occured, hence, a new substance has been formed. The formation of a new substance during the burning process (chemical reaction), induced the increase in mass.