Answer:
Explanation:
Work done in lifting the weight once = mgh
= 20 x 9.8 x (1.9+1.7)
= 705.6 J
= 705.6 / 4.2 calorie
= 168 cals
Total energy to be spent = 600 x 10³ cals
No of times weight is required to be lifted
= 600 x 10³ / 168
= 3.57 x 10³ times
Total time to be taken = 2 x 3.57 x 10³
= 7.14 x 10³ s
=119 minutes .
card games
board games
bird watch
write a song
make a game
count stuff
throw a ball with someone
play outside
Answer:
Changes in the object's momentum (answer D)
Explanation:
A net force will cause an object to change its velocity, and that will affect the object's momentum, which is defined by the product of the object's mass times its velocity.
So, select the last option (D) in the given list.
Answer:
3.528×10² V.
Explanation:
potential difference: This is the work done when one coulomb of charge moves from one point to another in an electric field. The S.I unit of potential difference is volt. The formula of potential difference is given as,
V = kq/r..................... Equation 1
And
E = kq/r² .................. Equation 2
Comparing equation 1 and equation 2,
V = E×r............................. Equation 3
Where V = potential difference, E = Electric field between the plate of the capacitor, r = distance between the plate.
Given: E = 6.3×10⁵ V/m, r = 0.56 mm = 0.00056 m.
Substitute into equation 3,
V = 6.3×10⁵×0.00056
V = 3.528×10² V.
Hence the potential difference of the plate = 3.528×10² V.