Answer:
west
Explanation:
The acceleration of an object is equal to the rate of change of velocity of the object, and it is given by:
where
u is the initial velocity
v is the final velocity
t is the time elapsed
For the object in this problem:
u = 65 m/s east is the initial velocity
v = 25 m/s east is the final velocity
t = 10 s is the time elapsed
Substituting, we find the acceleration:
And the negative sign tells that the direction of the acceleration is opposite to the direction of the velocity: so, the acceleration is west.
Answer:
3.14 m/s
Explanation:
We are given that
Mass of object=1.1 Kg
Spring constant=160 N/m
a.We have to find the amount by which the spring is stretched from its unstrained length(it means x)
We know that F=kx ,
b.When an object is pulled straight down by an additional distance 0.26 m and released from rest.
x=0.26 m
We have to find the speed with which the object passes through its original position on the way up.
(Law of conservation of energy)
Substitute the values then we get
Hence, the speed of an object with which the object passes through its original position on the way up=3.14 m/s
We have the relation
where denotes the velocity of a body A relative to another body B; here I use B for boat, E for Earth, and R for river.
We're given speeds
Let's assume the river flows South-to-North, so that
and let be the angle made by the boat relative to East (i.e. -90° corresponds to due South, 0° to due East, and +90° to due North), so that
Then the velocity of the boat relative to the Earth is
The crossing is 153.0 m wide, so that for some time we have
which is minimized when so the crossing takes the minimum 30.0 s when the boat is pointing due East.
It follows that
The boat's position at time is
so that after 30.0 s, the boat's final position on the other side of the river is
and the boat would have traveled a total distance of