Answer:
When an object is immersed in water. it is pulled downwards due to gravitational pull of earth. Water exerts upward force on the object. This makes object rise up. This upward force is called buoyancy or upthrust.
Answer:
Explanation:
We shall find electric field at origin due to two given charges sitting on the either side of origin .
Total field will add up due to their same direction .
Field due to a charge Q
= 9 x 10⁹ x Q / R² ; R is distance of point , Q is charge
Field due to first charge
= 9 x 10⁹ x 40 x 10⁻³ / 2² x 10⁻⁴
= 90 x 10¹⁰ N/C
Field due to second charge
= 9 x 10⁹ x 50 x 10⁻³ / 2² x 10⁻⁴
= 112.5 x 10¹⁰ N/C
Total field
= 202.5 x 10¹⁰ N/C
Force on given charge at origin
= charge x field
= 4 x 10⁻³ x 202.5 x 10¹⁰
= 810 x 10⁷ N .
Answer:
The mass of the skateboard is 1.25 kg.
Explanation:
We have,
Mass of dog, m = 5 kg
Initial speed of dog, u = 2.5 m/s
Initial speed of skateboard, u' = 0 (at rest)
The dog jumps onto the skateboard and both the dog and skateboard move with a speed of 2.00 m/s. It is the common speed of the dog +skateboard, V = 2 m/s. We need to find the mass of the skateboard. Using conservation of momentum as :
m' is mass of skateboard
So, the mass of the skateboard is 1.25 kg.
Answer:Falling objects form an interesting class of motion problems. For example, we can estimate the depth of a vertical mine shaft by dropping a rock into it and listening for the rock to hit the bottom. By applying the kinematics developed so far to falling objects, we can examine some interesting situations and learn much about gravity in the process.
Explanation:
Answer:
893 Newtons
Explanation:
m = Mass of Usain Bolt = 94 kg
a = Acceleration of Usain Bolt in the first 0.89 seconds = 9.5 m/s²
From Newton's Second law
Force
The average horizontal force exerted by Bolt against the ground during the first 0.890 s of the race is 893 Newtons
