Since they are rowing against the current, their velocity realtive to the groud is 20-1.5 = 18.5km/h
So the distance travelled is 18.5km/h*0.5h = 9.25km
Going back with the current their ground realative velocity is 20+1.5 = 21.5km/h so the time it takes them to return 9.25 km is 9.25km/(21.5km/h) = 0.43h ~= 26 min
Answer:
14.2 m
Explanation:
Using conservation of energy:
PE at top = KE at bottom
mgh = ½ mv²
h = v² / (2g)
h = (16.7 m/s)² / (2 × 9.8 m/s²)
h = 14.2 m
Using kinematics:
Given:
v₀ = 16.7 m/s
v = 0 m/s
a = -9.8 m/s²
Find: Δy
v² = v₀² + 2aΔy
(0 m/s)² = (16.7 m/s)² + 2 (-9.8 m/s²) Δy
Δy = 14.2 m
Ngan's mass on earth is 85kg.
Ngan has a weight on Mars = 14.5 N
Ngan’s weight on Earth = 833.0 N
Ngan’s mass on Earth = ?
<span>Fg,earth = mg(earth)</span>
<span>M = Fg,earth </span><span>/ g(earth)</span>
<span>M = 833.0 N / 9.8 m/s2</span>
<span>M = 85 kg</span>
