Answer:
The work done against gravity is 78.4 J
Explanation:
The work is calculated by multiplying the force by the distance that the
object moves
W = F × d, where W is the work , F is the force and d is the distance
The SI unit of work is the joule (J)
We need to find the work done against gravity when lowering a
16 kg box 0.50 m
→ F = mg
→ m = 16 kg, and g = 9.8 m/s²
Substitute these value in the rule
→ F = 16 × 9.8 = 156.8 N
→ W = F × d
→ F = 156.8 N and d = 0.50
Substitute these values in the rule
→ W = 78.4 J
<em>The work done against gravity is 78.4 J</em>
Answer:
a)
b)
c)
d)
e)
Explanation:
Given that:
- initial speed of turntable,

- full speed of rotation,

- time taken to reach full speed from rest,

- final speed after the change,

- no. of revolutions made to reach the new final speed,

(a)
∵ 1 rev = 2π radians
∴ angular speed ω:

where N = angular speed in rpm.
putting the respective values from case 1 we've


(c)
using the equation of motion:

here α is the angular acceleration



(b)
using the equation of motion:





(d)
using equation of motion:



(e)
using the equation of motion:



First one is D and Second one is B
Answer:
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