a) Let's call x the direction parallel to the river and y the direction perpendicular to the river.
Dave's velocity of 4.0 m/s corresponds to the velocity along y (across the river), while 6.0 m/s corresponds to the velocity of the boat along x. Therefore, the drection of Dave's boat is given by:
relative to the direction of the river.
b) The distance Dave has to travel it S=360 m, along the y direction. Since the velocity along y is constant (4.0 m/s), this is a uniform motion, so the time taken to cross the river is given by
c) The boat takes 90 s in total to cross the river. The displacement along the y-direction, during this time, is 360 m. The displacement along the x-direction is
so, Dave's landing point is 540 m downstream.
d) If there were no current, Dave would still take 90 seconds to cross the river, because its velocity on the y-axis (4.0 m/s) does not change, so the problem would be solved exactly as done at point b).
Answer:
Explanation:
Given
Initial speed 
distance traveled before coming to rest 
using equation of motion
where v=final velocity
u=initial velocity
a=acceleration
s=displacement
for 
using same relation we get
divide 1 and 2 we get
So a distance if 213.32 ft is required to stop the vehicle with 80 mph speed
Answer:
** incident ray.
Incident ray - the ray of light falling on the surface AB is called the incident ray
reflected ray.
** Reflected ray - the incident ray bouncing back in the same medium after striking the reflecting surface is called reflected ray.
The gravitational pull on moon A will be lower since it is further away from the new planet.
Examples of Newton's three law of motion.
First law of motion: A rocket being launched up in the atmosphere.
Second law of motion:while riding a bicycle, a bicycle acts as a mass and our legs pushing on the pedals of the bicycle is the force.
Third law of motion:when we jump off from the boat,the boat moves backward.
Hope,it will helpyouu!
