Answer:
The velocity of the boat with respect to the ground is 3 km/h
Explanation:
The speed of an object is different depending on the reference system you use. This is called relative speed.
A boat travels upstream, this means that it moves in the opposite direction to the river current.
A boat travels upstream, this means that it moves in the opposite direction to the river current. Then, if the boat moves in the positive direction of the x axis at 10 km / h with respect to the water of a river, the water flows in the negative direction of the x axis at 7 km / h with respect to the ground.
This causes the speed of the boat relative to the ground to be calculated as follows:
<em>VbG = Vbw - VwG
</em>
where VbG is the speed of the boat relative to the ground, Vbw is the speed of the boat relative to the water of the river and VwG is the speed of the water relative to the ground.
So: VbG=10 km/h – 7 km/h
<u><em>VbG= 3 km/h
</em></u>
The direction of this velocity is in the positive x-direction.
Answer:
22m/s
Explanation:
To find the velocity we employ the equation of free fall: v²=u²+2gh
where u is initial velocity, g is acceleration due to gravity h is the height, v is the velocity the moment it hits the ground, taking the direction towards gravity as positive.
Substituting for the values in the question we get:
v²=2×9.8m/s²×25m
v²=490m²/s²
v=22.14m/s which can be approximated to 22m/s
Answer:
I'd say C is the answer they want, though my pedantic side wants to argue for B being true as well.
Answer:
3054.4 km/h
Explanation:
Using the conservation of momentum
momentum before separation = 5M × 2980 Km/h where M represent the mass of the module while 4 M represent the mass of the motor
initial momentum = 14900 M km/h
let v be the new speed of the motor so that the
new momentum = 4Mv and the new momentum of the module = M ( v + 94 km/h )
total momentum = 4Mv + Mv + 93 M = 5 Mv + 93M
initial momentum = final momentum
14900 M km/h = 5 Mv + 93M
14900 km/h = 5v + 93
14900 - 93 = 5v
v = 2961.4 km/h
the speed of the module = 2961.4 + 93 = 3054.4 km/h
Explanation:
You need two, maybe three things - something that's vibrating, a medium for those vibrations to propagate in, and a listener to hear it or recording equipment to pick it up
