Answer:

Explanation:
We know that for circular motion the centripetal acceleration
is:

where v is the speed and r is the radius.
The centripetal acceleration for the astronaut must be the gravitational acceleration due to the gravity, as there are no other force. So
.
The radius of the orbit must be the radius of the Moon, plus the 270 km above the surface




We can obtain the speed as:






And this is the orbital speed.
Answer:
The voltage across light bulb 1 and light bulb 2 is the the same i.e V
Explanation:
In a parallel circuit, the Voltage is same across all the components of the circuit and the current flowing through each component is added to get the total current across the circuit.
Let us say, the voltage across the circuit is V. The voltage across light bulb 1 and light bulb 2 is the the same i.e V
<u>Answer:</u> The correct answer is Option b.
<u>Explanation:</u>
Young's Modulus is defined as the ratio of stress acting on a substance to the amount of strain produced.
Stress is defined as force per unit area and strain is defined as proportional deformation in a material.
The equation representing Young's Modulus is:

where,
Y = Young's Modulus
F = force exerted by the weight
l = length of wire
A = area of cross section
= change in length
Hence, the correct answer is Option b.
Answer: the sun's rays is one of the raw Materials recquired by plants to make food
Explanation:plants trap light used in splitting water into hydrogen ions and oxygen molecules
Answer:
805m
Explanation:
Speed = displacement/time
Speed = 23m/s
Time = 35s
Displacement = speed × time
= 23 × 35
= 805m