Answer:
Mass of the planet = 6.0 × 
Explanation:
Time period = 2π (R + h) / v
Orbital speed (v) = √GM / (R + h)
T² = 4π² (R + h)² / (GM/ (R + h))
= 4π² (R + h)³ / GM
making m the subject of the formula
m = 4π² (R + h)³ / GT²
= 4π² ( 6.38 ×
+ 230 × 10³ )³ / ( 6.67 ×
) × (89 × 60)²
= 4π² ( 6610000)³ / ( 6.67 ×
) × (89 × 60)²
= 5.99 × 
= 6.0 × 
Answer:

Explanation:
When the screw is turned by two turns then change in the length of the wire is given as




now we know by the formula of Young's modulus

so we have



Answer:
r = 50.47 x 10³ m = 50.47 km
Explanation:
Using the formula for the acceleration due to gravity:

where,
g = acceleration due to gravity on the surface of asteroid = 0.0288 m/s²
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ Nm²/kg²
m= mass of asteroid = 1.1 x 10¹⁸ kg
r = radius of asteroid = ?
Therefore,

<u>r = 50.47 x 10³ m = 50.47 km</u>
Answer:
(C) length / height of the plane
Explanation:
The mechanical advantage of an inclined plane can be determined using different variables. In this case, the geometry of the setup is relevant. The advantage is proportional to the length of the plane, and inversely proportional to the height: it is the ratio (length) / (height) of the plane. For example, given a desired, fixed height, a long inclined plane gives you a bigger mechanical advantage than a short inclined plane. In this example, pushing an object up the long plane will require a smaller force, than it would on the short plane.
Strictly speaking, (D) would also "allow you to determine the mechanical advantage" because you could simply invert the ratio listed under (D). However, (C) is the best, direct, answer.