QUESTION 1 A 20 kg block, resting on rough horizontal surface, is connected to blocks P and Q by a light
inextensible string, moving over a frictionless pulley. Blocks P and Q are glued together and
have a combined mass of m. A force of 35 N is now applied to the 20 kg block at an angle of 40°
with the horizontal as shown below.
35 N
20 kg
P
The 20 kg block experiences a frictional force of magnitude of 5 N as it moves to the RIGHT at a
CONSTANT SPEED.
(2)
Calculate the combined mass m of the two blocks

The a metal retainer that keeps the rolling elements evenly spaced. n a. seal n b. separator n c. bearing n d outer race

There is a theory that indicates that dinosaurs became extinct when about 65 million years ago, a large asteroid hit the earth surface. dust caused by this collision blocked the sunlight reaching the earth's surface and many forms of life became extinct due to the cold. fearing this threat, how large the radius of an asteroid should you be looking for if the dangerous asteroid size is approximately the same as the one that killed the dinosaurs? available data suggests that about 18% of that asteroid's mass ended up as a dust spread evenly over earth after eventually settling out of the upper atmosphere. about 0.0180 g/cm^2 of dust, which is chemically different than the earth's rock, covered the earth's surface. typical asteroids have a density of about 1.9 g/cm^3. now that we know the size of the asteroid, how much energy was released during impact, assuming all of it was just the kinetic energy of the asteroid right before the impact?

Which is not true about oxygen-17 and oxygen-18?